refactor(versal2): guard handoff logic w/ build flag

Prepare for environments where the Firmware Handoff (LibTL) submodule
may not be available. Wrap all Transfer List dependent logic in `#if
TRANSFER_LIST` guards, ensuring the platform can build and run without
the submodule.

This is useful for builds not integrating the firmware handoff
mechanism.

Change-Id: Ia34bc0f4d352a3014c71eda6589c0f3e0a107ca0
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
diff --git a/plat/amd/versal2/bl31_setup.c b/plat/amd/versal2/bl31_setup.c
index 94ace7d..28bcaa1 100644
--- a/plat/amd/versal2/bl31_setup.c
+++ b/plat/amd/versal2/bl31_setup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2025, Arm Limited and Contributors. All rights reserved.
  * Copyright (c) 2018-2022, Xilinx, Inc. All rights reserved.
  * Copyright (c) 2022-2025, Advanced Micro Devices, Inc. All rights reserved.
  *
@@ -27,7 +27,9 @@
 #include <plat_fdt.h>
 #include <plat_private.h>
 #include <plat_startup.h>
+#if TRANSFER_LIST
 #include <plat_xfer_list.h>
+#endif
 #include <pm_api_sys.h>
 #include <pm_client.h>